The present invention concerns an electronic lock able to be unlocked by a key having a right of access recognised by an identification code.
At the current moment, most of the conventional or safety locks available on the market are mechanical locks. However, there are certain locks, namely electromechanical locks, which match conventional mechanical coding (resulting from the profile often produced from the blade of the key) with an electronic coding.
Furthermore, the patent U.S. No. 4,856,310 describes another type of lock, known as an electronic lock able to be locked and unlocked from comparing an identification code present in both the lock and the key without it being necessary to add to it any additional mechanical coding. However, this type of lock, which is fully electronic, is still not available on the market, and in fact there are good reasons for this, namely that it still has a number of particularly significant drawbacks which in practice prevents it from being commercialised. First of all, if for example the key is lost, it proves to be impossible to modify the identification, codes without contacting the manufacturer of the lock. In addition, the feeding of these locks with energy is assumed to be effected by batteries which constitutes a problem having regard to their limited periods of life. Finally, the internal structure of these locks and in particular their barrel is still particularly complex (as often merely adapted from conventional mechanical locks) and especially less reliable as shown by the structure of the barrel (basically from several springs compressed in the rest position) of said patent.
This first two problems have fortunately been resolved. In fact, with the European patent application EP-A-805-906, the Luxembourg company Electronic key systems (EKS) limited has resolved the problem of modifying the identification code of the lock by adding programming means to the key enabling the user to directly carry out this modification. Similarly, the feeding with energy problem was also resolved shortly afterwards by the international PCT patent application WO 97/48867 filed in the name of this same company which proposed using a key having autonomous energy generation means. Thus, it merely remains to currently find for these electronic locks a simple barrel structure to finally, and contrary to all expectations, enable these locks to be commercialised.
Thus, the object of the present invention is to provide an electronic barrel with a simple structure adapted to an electronic environment and comprising in particular an extremely limited number of internal parts. One aim of the invention is also to provide a particularly reliable (sturdy) and high-performance barrel with a reduced energy consumption. A further aim is to obtain a barrel fully protected from impacts, vibrations or dust. Again, another aim of the invention is to produce a barrel resistant to tearing, sinking in or picking (anti forcible entry protection). Another aim is also to be able to easily manage key conflicts.
These aims can be obtained by providing an electronic barrel comprising a barrel body and a rotary-lock key bit, the barrel body comprising at least one rotor having a common axis with the body and the rotary-lock key bit and freely rotating inside said body, a clutch part coupled in rotation with the rotor and comprising meshing means co-operating with additional means of the key bit so as to drive in rotation said key bit by the rotor by the action of a rotating torque of the key, and locking means for preventing the clutch part from being translated when there is no recognition of an identification code transmitted between the key and the barrel, characterised in that said locking means are further mounted integral in the rotary-lock key bit and in that said rotor is mobile in translation for thrusting the clutch part towards the key bit when said identification code is recognised.
By means of this structure with a particularly limited number of mechanical parts, movement of the key bit can be easily effected through the clutch part from the single rotation torque of the key without control of the locking (unlocking) means requiring a great amount of energy.
The stop of the electronic barrel is preferably constituted by a single protection flap pivoting around an axis parallel to the axis of at least one rotor between an initial position and a final freeing position. The protection flap acts against the action of a return spring for automatically bringing back this flap into its initial position when the key is removed.
The motor means preferably comprise an electric microactuator with an axis parallel to the axis of at least one rotor, the freeing of at least one stop being carried out by means of a drive pinion borne by a final drive shaft of the electric microactuator and gearing on a sector gear integral with the stop.
The clutch part is formed of a cylindrical ring fitted with a central disk and comprising on both sides of this central disk groove-shaped mesh means for providing linking in rotation firstly with the key bit and secondly with the rotor. The central disk of the clutch part comprises a central heel for co-operating with the stop for freeing this part.
According to one embodiment characteristic, the electronic barrel further comprises at least one compression spring inserted between the rotor and the clutch part. It may further comprise at least one return clamp integral with the rotor and intended to co-operate with the clutch part to enable it to be freed from the key bit when the key is removed. The return clamp preferably comprises an annular disk fitted with at least one foot traversing the clutch part and fixed to the rotor, the disk co-operating with a surface of the clutch part perpendicular to the axis of at least one rotor.
According to another embodiment characteristic, the electronic barrel further comprises at least one circlip integral with the body of the barrel and intended to limit the translation of at least one rotor in the direction of the key bit.
Again, according to another embodiment characteristic, the electronic barrel comprises at least one disengaging finger formed of two independent portions spaced by a single compression spring and intended to ensure locking of the key in the rotor so as to enable the clutch part to be freed from the rotary key bit when the key is removed. This disengaging finger is preferably mounted perpendicular to the axis of at least one rotor in an opening partly traversing the rotor, a first extremity of this disengaging finger being flush inside the key pipe so as to come into contact with an orifice of the key and a second extremity going past the external wall of the rotor so as to come into contact with a longitudinal groove of the internal wall of the body of the barrel. The groove of the internal wall of the body of the barrel may comprise at least one slanted portion to facilitate compression of the sole spring when the rotor is moved after the key is introduced. Thus, the removal of the key is impossible outside an angular position defined by the precise location of the groove.
The key bit preferably comprises an annular conductive track for co-operating with a sole fixed electric contact of the body of the barrel so as to provide it with energy from motor means. Similarly, the barrel body comprises at least one perforation perpendicular to the axis of at least one rotor for receiving an electric contact, preferably of the ball type, so as to co-operate with a corresponding conductive element of the key. Electronic circuits placed in a cavity of the body of the barrel and connected firstly to at least one electric ball contact and secondly to the sole fixed electric contact are further provided so that feeding from the motor means of the key bit can be effected directly from the key through the electronic circuits.
According to a preferred embodiment, the electronic barrel of the invention comprises a first rotor or internal rotor and a second rotor or external rotor, and the width of the protection flap of the external rotor is larger than that of the protection flap of the internal rotor so that the introduction of a key into the external key pipe does not allow driving of the key bit in the presence of a key not recognised in the internal key pipe. In this case, at least one linking barrel with a length greater than the width of the key bit placed at the level of this key bit btween the return clamps, this linking barrel being intended to co-operate with the latter so as to prevent the simultaneous engaging of the internal and external rotors when two keys are introduced into the two key pipes.
The invention also concerns a lock with one or two rotors fitted with an electronic barrel as mentioned above.